I remember playing Rockman World for the Gameboy on Elec Man's man, I was trying to get to past the first part of the level only to get hit by an enemy and I landed on the spikes. While this isn't limited to classic series, does anyone else have some experience with collision damage?

I've taken it for granted so much that when I got a suit in Aquaria that lets you deal collision damage to the enemies (while you become immune to it) it was mind-blowing. The ability to move through any enemy that isn't a boss... yeah, used that one for most of the game after that.